US11479704B2 - Potassium salt treatment fluids for clay stabilization - Google Patents
Potassium salt treatment fluids for clay stabilization Download PDFInfo
- Publication number
- US11479704B2 US11479704B2 US16/476,982 US201816476982A US11479704B2 US 11479704 B2 US11479704 B2 US 11479704B2 US 201816476982 A US201816476982 A US 201816476982A US 11479704 B2 US11479704 B2 US 11479704B2
- Authority
- US
- United States
- Prior art keywords
- fluid
- potassium
- clay
- wellbore
- potassium salt
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active, expires
Links
- 239000012530 fluid Substances 0.000 title claims abstract description 225
- 239000004927 clay Substances 0.000 title claims abstract description 134
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 title claims abstract description 52
- 238000011282 treatment Methods 0.000 title claims description 115
- 230000006641 stabilisation Effects 0.000 title description 3
- 238000011105 stabilization Methods 0.000 title description 3
- 239000003381 stabilizer Substances 0.000 claims abstract description 93
- 238000005553 drilling Methods 0.000 claims abstract description 45
- 150000001768 cations Chemical class 0.000 claims abstract description 32
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 17
- 230000008961 swelling Effects 0.000 claims abstract description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 22
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 claims description 14
- -1 carnillite Chemical compound 0.000 claims description 12
- 150000003839 salts Chemical class 0.000 claims description 11
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 10
- 239000011591 potassium Substances 0.000 claims description 10
- 229910052700 potassium Inorganic materials 0.000 claims description 10
- 239000004215 Carbon black (E152) Substances 0.000 claims description 7
- 235000011126 aluminium potassium sulphate Nutrition 0.000 claims description 7
- 239000012267 brine Substances 0.000 claims description 7
- 229930195733 hydrocarbon Natural products 0.000 claims description 7
- 150000002430 hydrocarbons Chemical class 0.000 claims description 7
- GRLPQNLYRHEGIJ-UHFFFAOYSA-J potassium aluminium sulfate Chemical compound [Al+3].[K+].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GRLPQNLYRHEGIJ-UHFFFAOYSA-J 0.000 claims description 7
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 claims description 7
- 241001131796 Botaurus stellaris Species 0.000 claims description 6
- WZISDKTXHMETKG-UHFFFAOYSA-H dimagnesium;dipotassium;trisulfate Chemical compound [Mg+2].[Mg+2].[K+].[K+].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O WZISDKTXHMETKG-UHFFFAOYSA-H 0.000 claims description 6
- AAQNGTNRWPXMPB-UHFFFAOYSA-N dipotassium;dioxido(dioxo)tungsten Chemical compound [K+].[K+].[O-][W]([O-])(=O)=O AAQNGTNRWPXMPB-UHFFFAOYSA-N 0.000 claims description 6
- RNGFNLJMTFPHBS-UHFFFAOYSA-L dipotassium;selenite Chemical compound [K+].[K+].[O-][Se]([O-])=O RNGFNLJMTFPHBS-UHFFFAOYSA-L 0.000 claims description 6
- 150000004677 hydrates Chemical class 0.000 claims description 6
- GMLLYEDWRJDBIT-UHFFFAOYSA-J magnesium;dipotassium;disulfate Chemical compound [Mg+2].[K+].[K+].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GMLLYEDWRJDBIT-UHFFFAOYSA-J 0.000 claims description 6
- BMQVDVJKPMGHDO-UHFFFAOYSA-K magnesium;potassium;chloride;sulfate;trihydrate Chemical compound O.O.O.[Mg+2].[Cl-].[K+].[O-]S([O-])(=O)=O BMQVDVJKPMGHDO-UHFFFAOYSA-K 0.000 claims description 6
- RWPGFSMJFRPDDP-UHFFFAOYSA-L potassium metabisulfite Chemical compound [K+].[K+].[O-]S(=O)S([O-])(=O)=O RWPGFSMJFRPDDP-UHFFFAOYSA-L 0.000 claims description 6
- 229940043349 potassium metabisulfite Drugs 0.000 claims description 6
- 235000010263 potassium metabisulphite Nutrition 0.000 claims description 6
- LJCNRYVRMXRIQR-OLXYHTOASA-L potassium sodium L-tartrate Chemical compound [Na+].[K+].[O-]C(=O)[C@H](O)[C@@H](O)C([O-])=O LJCNRYVRMXRIQR-OLXYHTOASA-L 0.000 claims description 5
- 239000001476 sodium potassium tartrate Substances 0.000 claims description 5
- 235000011006 sodium potassium tartrate Nutrition 0.000 claims description 5
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 229940096405 magnesium cation Drugs 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 4
- KVLCHQHEQROXGN-UHFFFAOYSA-N aluminium(1+) Chemical compound [Al+] KVLCHQHEQROXGN-UHFFFAOYSA-N 0.000 claims description 3
- 229940007076 aluminum cation Drugs 0.000 claims description 3
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims 1
- 238000005755 formation reaction Methods 0.000 abstract description 16
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 51
- 229940037003 alum Drugs 0.000 description 25
- 239000001103 potassium chloride Substances 0.000 description 24
- 235000011164 potassium chloride Nutrition 0.000 description 24
- 238000012360 testing method Methods 0.000 description 21
- 238000010438 heat treatment Methods 0.000 description 12
- 239000004033 plastic Substances 0.000 description 11
- 229910001414 potassium ion Inorganic materials 0.000 description 6
- 230000005012 migration Effects 0.000 description 5
- 238000013508 migration Methods 0.000 description 5
- 229920000768 polyamine Polymers 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000000638 stimulation Effects 0.000 description 4
- 238000005520 cutting process Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000012065 filter cake Substances 0.000 description 3
- 239000013505 freshwater Substances 0.000 description 3
- 230000036571 hydration Effects 0.000 description 3
- 238000006703 hydration reaction Methods 0.000 description 3
- 230000005764 inhibitory process Effects 0.000 description 3
- 238000000518 rheometry Methods 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 235000015076 Shorea robusta Nutrition 0.000 description 2
- 244000166071 Shorea robusta Species 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 150000001336 alkenes Chemical class 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- ZZUFCTLCJUWOSV-UHFFFAOYSA-N furosemide Chemical compound C1=C(Cl)C(S(=O)(=O)N)=CC(C(O)=O)=C1NCC1=CC=CO1 ZZUFCTLCJUWOSV-UHFFFAOYSA-N 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 229910021647 smectite Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/14—Clay-containing compositions
- C09K8/16—Clay-containing compositions characterised by the inorganic compounds other than clay
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K2208/00—Aspects relating to compositions of drilling or well treatment fluids
- C09K2208/12—Swell inhibition, i.e. using additives to drilling or well treatment fluids for inhibiting clay or shale swelling or disintegrating
Definitions
- the present disclosure relates to treatment fluids and methods for using treatment fluids in a wellbore.
- the present disclosure relates more particularly to clay stabilizers that include a potassium salt that include a plurality of cations that can be used in wellbore operations.
- Clay stabilizers are chemical additives used in treatment fluids of wellbore operations, often used in stimulation treatments that maintain, restore, or enhance the productivity of a well.
- a water-based drilling fluid is often used.
- the clay in the wellbore can absorb water from the drilling fluid and swell in reaction to contact with the water-based fluid.
- the electrical charge of naturally occurring clay platelets in a subterranean formation can be affected. Modifying the charge can cause the platelets to disperse and migrate into the flowing drilling fluid. Once platelets are dispersed, some clay plugging of the formation can occur.
- Clay stabilizers can prevent the migration or swelling of clay particles by altering the electrical charge of the clay platelets and minimize or prevent the clay from swelling or migrating into the flowing drilling fluid, which can plug the wellbore.
- Clay stabilizers act to retain the clay platelets in position by controlling the charge and electrolytic characteristics of the treatment fluid. By retaining and stabilizing the clay platelets, plugging of the wellbore can be reduced or eliminated, allowing the productivity of the well to be maintained or enhanced.
- Potassium chloride is a conventional clay stabilizer used in treatment fluids of wellbore operations. Potassium chloride (KCl) is a single-cation soluble salt that is an efficient shale stabilizer when drilling hydro sensitive clays and shales.
- the potassium ion (K+) specifically its charge and size, helps provide stability to the clay in the formation.
- potassium chloride is in high demand and alternative sources of potassium ion for clay stabilizers are desired.
- FIG. 1 is an illustrative schematic of a drilling assembly using a drilling fluid according to one or more embodiments described herein.
- FIG. 2 is a table showing rheological properties of treatment fluids with a clay stabilizer according to one example of the present disclosure.
- FIG. 3 is a table showing capillary suction time (CST) results of treatment fluids with a clay stabilizer according to one example of the present disclosure.
- CST capillary suction time
- FIG. 4 is a block diagram showing treatment fluids with a clay stabilizer used in wellbores according to one example of the present disclosure.
- the treatment fluids can include a drilling fluid and a clay stabilizer having a potassium salt comprising a plurality of cations.
- the potassium salt can be a double salt.
- Clay stabilizers are chemical additives used in treatment fluids of wellbore operations, often used in stimulation treatments that maintain, restore, or enhance the productivity of a well.
- clay in the wellbore can absorb water from the drilling fluid and swell in reaction to contact with the water-based fluid, affecting the electrical charge of naturally occurring clay platelets in a subterranean formation.
- Clay stabilizers can inhibit the migration or swelling of clay particles by altering the electrical charge of the clay platelets and minimize or prevent the clay from swelling or migrating into the flowing drilling fluid.
- a clay stabilizer can have a potassium salt that includes a plurality of cations.
- the potassium salt may include a potassium cation and a magnesium cation or a potassium cation and an aluminum cation.
- the clay stabilizer may be a double salt that includes potassium.
- the clay stabilizer may be a triple salt that includes potassium.
- Inhibition can be achieved through ion exchange with a potassium-containing clay stabilizer where the potassium ion enters the clay formation between the individual clay platelets in the shale so that they are held together, thus restricting the entry of water from the drilling fluid.
- the charge and size of the potassium ion can help retain the clay platelets in position and prevent swelling and migration of clay platelets in the formation.
- the ionic radius of a potassium ion which is about 2.66 ⁇ , is similar in size to the spacing between layers in swelling clays such as smectite, which is about 2.8 ⁇ . This similarity allows the potassium ion to fit snugly between unit layers, forming a bond that can inhibit swelling of the clay in the presence of water.
- a potassium ion also has low hydration diameter (7.6 ⁇ ) as compared to other monovalent and divalent cations such as Li, Na, Ca, Mg, Al etc.
- a low hydration diameter is desirable to help reduce clay swelling.
- the clay stabilizer can include potash alum, carnillite, langbeinite, polyhalite, potassium metabisulfite, potassium selenite, potassium tungstate, sodium potassium tartrate, kainite, potassium schoenite, bittern, or the hydrates thereof.
- the potassium salt comprising a plurality of cations can be present a treatment fluid in an amount ranging from about 0.1 wt. % to about 5.0 wt. %.
- the treatment fluid can include a potassium salt comprising a plurality of cations in amount from about 0.5 to about 5 wt. %, about 0.1 to about 1 wt. %, about 1 wt. % to about 3 wt. %, or about 2 wt. % to about 4 wt. %.
- the treatment fluid also includes a drilling fluid.
- the drilling fluid may include water, a brine, or a hydrocarbon fluid.
- the water may be fresh water, seawater, or salt water, for example.
- the hydrocarbon fluid may be mineral oils, biodegradable esters, olefins, or other variants.
- FIG. 1 illustrates a wellbore 44 being drilled through a subterranean formation 42 .
- a drill rig 40 can be used for drilling the wellbore 44 .
- a drill bit 50 may be mounted on the end of a drill string 52 that includes multiple sections of drill pipe.
- the wellbore 44 may be drilled by using a rotary drive at the surface to rotate the drill string 52 and to apply torque and force to cause the drill bit 50 to extend through wellbore 44 .
- a drilling fluid may be displaced through the drill string 52 using one or more pumps 54 .
- the drilling fluid may be circulated past the drill bit 50 and returned to the surface through the annulus of wellbore 44 , as indicated by arrows 46 , thereby removing drill cuttings (e.g., material such as rock generated by the drilling) from the wellbore 44 .
- a treatment fluid including a clay stabilizer can be added to the drilling fluid.
- additional conduits besides drill string 52 may also be disposed within wellbore 44 .
- Capillary-suction-time (CST) tests can be used to compare the effects of aqueous fluids on the tendency for clay swelling or dispersion and evaluate the effectiveness of treatment fluids with clay stabilizers.
- CST tests are a static filtration test that measure filtration rate as determined by the time for water to pass a standard distance between two electrodes, with filter paper as the medium.
- CST can indicate filter-cake permeability, behavior of clays and shales in filter cakes, and the effect of brine composition on clays in a filter cake.
- CST can be used as a direct indication that clay platelets have absorbed water and migrating within a clay sample.
- CST can also be used as a direct indication that the clay has stopped swelling and stabilized after stimulation treatment with the clay stabilize.
- the lower the CST result the faster water can pass between the test electrodes, indicating the path between the electrodes is not obstructed or plugged with clay.
- a decrease in CST value of a clay sample post-stimulation treatment can indicate that the clay stabilizer have altered the charge and stability of the clay.
- a low CST result is desirable as in indication that a wellbore is not plugged or have restricted flow.
- a treatment fluid with a clay stabilizer having a potassium salt comprising a plurality of cations has a CST result at least 20% lower than a treatment fluid with a comparison clay stabilizer, where the concentration of clay stabilizer is substantially the same in each fluid.
- a comparison clay stabilizer utilizes potassium chloride rather than a potassium salt comprising a plurality of cations as described herein.
- a treatment fluid with clay stabilizers having a potassium salt comprising a plurality of cations can have a CST result over 50% lower than a treatment fluid with a comparison clay stabilizer.
- CST results comparable to comparison clay stabilizers can be achieved with much lower concentrations of clay stabilizers having a potassium salt comprising a plurality of cations.
- Reduced concentrations of clay stabilizers may be advantageous to lower material consumption, lower operating costs, maintain fluid properties, and limit potential environmental impacts of drilling the wellbore as compared to conventional clay stabilizers that include a comparison clay stabilizer.
- Rheological tests can be used as an indirect method to evaluate the effectiveness of a treatment fluid to stabilize a subterranean formation and the degree of swelling in a clay sample treated with a treatment fluid.
- a viscometer can be used to measure rheological properties of a treatment fluid, including Bingham plastic model properties of yield point (VP) and plastic viscosity (PV). In some cases, a direct-indicating viscometer can be used.
- VP can be used to evaluate the ability of a drilling fluid to lift cuttings out of the wellbore during drilling.
- a high YP implies a non-Newtonian fluid, one that carries drill cuttings to the surface better than a fluid of similar density but lower YP.
- a low VP can indicate that the clay platelets in the formation are not migrating to the drilling fluid. Clay platelets in the drilling fluid would increase the viscosity of the fluid, and potentially plug the well.
- VP can be determined from a plot of shear stress and shear rate by extrapolating the yield stress of a fluid to a shear rate of zero or using a direct viscometer according to Eq.
- PV is a measure of the viscosity of a drilling fluid when extrapolated to infinite shear rate.
- a low PV indicates that a drilling fluid is capable of drilling rapidly because of the low viscosity of drilling fluid.
- a high PV can be caused by a viscous base fluid and can indicate that clay platelets in the formation are migrating to the drilling fluid, increasing the viscosity of the fluid, and potentially plugging the well.
- a low yield point plastic viscosity (PV) and yield point (VP) result is desirable for treatment fluids with clay stabilizers, which can indicate that the clay platelets are not migrating into the drilling fluid and plugging the wellbore.
- treatment fluids with a clay stabilizer having a potassium salt comprising a plurality of cations has a VP result lower than a treatment fluid with a comparison clay stabilizer, where the concentration of clay stabilizers in each treatment fluid is substantially the same.
- Treatment fluids with clay stabilizers having a potassium salt comprising a plurality of cations can have a VP result over 60% lower than treatment fluids with a comparison clay stabilizer.
- VP results comparable to a comparison clay stabilizer can be achieved with much lower concentrations of clay stabilizers having a potassium salt comprising a plurality of cations.
- a treatment fluid with a clay stabilizer having a potassium salt comprising a plurality of cations has a PV result lower than a treatment fluid with a comparison clay stabilizer, where the concentration of clay stabilizers is substantially the same.
- a treatment fluid with a clay stabilizer having a potassium salt comprising a plurality of cations can have a PV result over 60% lower than a treatment fluid with a comparison clay stabilizer.
- PV results comparable to a comparison clay stabilizer can be achieved with much lower concentrations of clay stabilizers having a potassium salt comprising a plurality of cations.
- lower in PV and VP results for potassium salt comprising a plurality of cations as compared to a comparison clay stabilizer can be present both before heat treatment and after heat treatment of the treatment fluid.
- the treatment fluid can be heated to simulate the conditions of a wellbore, where the treatment fluid can significantly increase in temperature.
- a sample may be heated in a rolling or tumbling apparatus to ensure the fluid remains mobile during the heating period.
- the treatment fluid may be heated to 100° F. to 400° F.
- the treatment fluid may be maintained at temperature for a time period of 1 hour to 20 hours. For example, a treatment fluid may be heated 150° F. and held at temperature for sixteen hours.
- shale stabilizers such as amine-based shale stabilizers
- a treatment fluid with a clay stabilizer having a potassium salt comprising a plurality of cations has a YP result over 90% lower than a treatment fluids with a shale stabilizer that includes ethoxylated polyamine, where the concentration of the clay stabilizers is substantially the same.
- a treatment fluid with clay stabilizers having a potassium salt comprising a plurality of cations can have a YP result over 90% lower than a treatment fluid with a shale stabilizer that includes ethoxylated polyamine.
- clay stabilizers having a potassium salt comprising a plurality of cations provide opportunities for reduced consumption of clay stabilizers and potential reduction in raw material costs to achieve similar results to conventional potassium chloride stabilizers or commercial shale stabilizers.
- a potassium salt comprising a plurality of cations may be contacted with a drilling fluid to produce a treatment fluid.
- a wellbore in a shale or clay formation can be treated with the treatment fluid to stimulate production in the wellbore.
- the potassium salt comprising a plurality of cations and the drilling fluid may be mixed or combined to be substantially homogenous.
- a wellbore in a shale or clay formation can be treated with the treatment fluid where the potassium salt comprising a plurality of cations clay stabilizer can include potash alum, carnillite, langbeinite, polyhalite, potassium metabisulfite, potassium selenite, potassium tungstate, sodium potassium tartrate, kainite, potassium schoenite, bittern, or hydrates thereof.
- the wellbore can be treated with a treatment fluid having a potassium salt comprising a plurality of cations present in an amount within a range of about 0.1 wt. % to about 5.0 wt. %.
- the treatment fluid can include a potassium salt comprising a plurality of cations in an amount from about 0.5 to about 5 wt. %, about 0.1 to about 1 wt. %, about 1 wt. % to about 3 wt. %, or about 2 wt. % to about 4 wt. %.
- a wellbore in a shale or clay formation can be treated with the treatment fluid where the drilling fluid includes water, brine, or a hydrocarbon fluid.
- Treating a wellbore with a treatment fluid that includes a drilling fluid and a clay stabilizer may include introducing the treatment fluid into a wellbore.
- the treatment fluid may be injected into the wellbore.
- Treating a wellbore with a treatment fluid can include a step of circulating the treatment fluid in a wellbore.
- the treatment fluid can be circulated to allow the clay stabilizers having a potassium salt comprising a plurality of cations to contact the clay within the wellbore and modify a charge of the clay platelets to reduce or eliminate swelling or migration of the platelets.
- a sample of the treatment fluid can be taken while circulating within a wellbore.
- the sample can be tested for rheological properties of the treatment fluid to evaluate the amount of plugging within the wellbore.
- a CST test, a shale erosion test, or a linear swell test can be performed on a treatment fluid at various points during treatment.
- the effectiveness of the treatment can be determined by changes in the properties of the treatment fluid as it is contacted with the clay of the wellbore.
- testing can include determining of plastic viscosity or yield point.
- the treatment fluid may be circulated until a threshold value for CST, plastic viscosity, or yield point is reached.
- the treatment fluid may be circulated until a targeted level of reduction in the CST, plastic viscosity, or yield point value is reached.
- a system may include a mixer 401 that contacts a clay stabilizer having a potassium salt comprising a plurality of cations and a drilling fluid to form a treatment fluid and an injection pump 403 to inject the treatment fluid into a wellbore.
- a system for treating a wellbore with a treatment fluid can include a circulation pump 407 to circulate a treatment fluid within a wellbore.
- the system may also include a sample port (not shown) to pull samples of the treatment fluid as it is circulated within a wellbore 405 .
- the treatment fluid may be packaged into barrels or other containers and placed in storage for future use. Once the wellbore stimulation treatment is complete, the treatment fluid may be send for waste or recycle.
- Treatment fluids were prepared using a barrel of fresh water and adding a known amount of clay stabilizer to the barrel.
- Treatment fluids were prepared with 1 wt. %, 2 wt. %, and 3 wt. % of clay stabilizer.
- Clay stabilizers tested included a shale stabilizer that includes ethoxylated polyamine, potash alum (“K-Alum”), and potassium chloride (“KCl”). Once the clay stabilizer was dissolved in the water, the pH of the solution was adjusted to about nine using caustic. 30 g of a bentonite viscosifier was then added to each treatment fluid.
- Each barrel was mixed for twenty minutes.
- a FANN® viscometer was used to measure the rheology of each treatment fluid.
- Each treatment fluid was hot rolled at 150° F. for sixteen hours.
- the rheology tests before the sample was hot rolled (“BHR”) and after the sample was hot rolled (“AHR”) were conducted at 120° F.
- the control was AGS and water, without any stabilizer. The results are tabulated in FIG. 2 .
- the treatment fluid with 1% KCl had a YP of 19 lb/100 ft 2
- a treatment fluid with 1% K-Alum had a VP of 6 lb/100 ft 2
- a FANN® viscometer at 120° F. prior to heat treatment.
- the KCl sample experienced a slight increase in VP while the K-Alum sample experienced a decrease.
- the VP of K-Alum sample remained significantly lower than VP of the KCl sample.
- the treatment fluid with 3% KCl had a YP of 3 lb/100 ft 2
- the YP of the K-Alum sample was lower than the KCl both before and after heat treatment of the treatment fluid.
- the treatment fluid with 1% KCl had a PV of 3 cp, whereas as a treatment fluid with 1% K-Alum had a PV of 1 cp, as determined by a FANN® viscometer at 120° F., prior to heat treatment.
- the PV of the K-Alum sample was lower than the KCl both before and after heat treatment of the treatment fluid.
- the treatment fluid with 3% KCl had a PV of 1 cp, whereas as a treatment fluid with 1% K-Alum had a PV of 1 cp, prior to heat treatment.
- the treatment fluid with 1% a shale stabilizer that includes ethoxylated polyamine had a VP of 76 cp, whereas as a treatment fluid with 1% K-Alum had a PV of 1 cp, as determined by a FANN® viscometer at 120° F., prior to heat treatment.
- the lower YP of the K-Alum sample was present both before and after heat treatment of the treatment fluid.
- the K-Alum sample showed the least amount of clay swelling as compared to other clay stabilizers or the control according to the rheological tests. It was also observed that K-Alum was effective even at low concentration of 1 to 2%, indicating that a potential benefit of reduced consumption was possible. The results for 3% K-Alum and 3% KCl were found to be similar. When compared to the shale stabilizer that includes ethoxylated polyamine, both salt based systems, KCl and K-Alum, showed better performance.
- the inhibition of the K-Alum salt and KCl salt was also evaluated by CST analysis on London Clay as a representative shale.
- the CST served as a proxy to determine the shale inhibition of London Clay.
- Different concentrations of both K-Alum and KCl were prepared and tested for CST by determining the time to pass across a fixed radial distance (i.e., a one-inch gap) between electrodes arranged in a triangular manner.
- the test blotter paper was placed on the top of the sensor trays, and the sensor plates were placed with the electrode side down on top of the test blotter paper.
- the stainless steel funnel was then placed into the gap between the sensor plates. Approximately 2.0 g of a clay (shale) sample and 24 mL of a salt solution were placed in a blender and mixed. Approximately 4 mL of the mixture was injected into the stainless steel funnel.
- the CST meter determined the time for the fluid to cross between the electrodes, the time for the fluid to contact the third electrode after contacting the first two electrodes. The test was repeated and the average of three test results was then recorded.
- the CST results are summarized in FIG. 3 .
- the treatment fluid with 1% KCl had an average CST result of 192 seconds, whereas as the treatment fluid with 1% K-Alum had an average CST result of 98 seconds.
- a treatment fluid with 5% KCl had an average CST result of 115 seconds, whereas as a treatment fluid with 0.5% K-Alum had an average CST result of 106 seconds.
- K-Alum even low concentrations was found to have low CST results, indicating high shale stabilization, i.e., low migration of platelets.
- a concentration as low as 0.25% K-Alum resulted in average CST of 130-140 seconds.
- K-Alum concentration 0.5 to 0.75% resulted in lower CST.
- the 1% K-Alum sample resulted in best performance with an average CST of about 98-100 seconds, indicating that the fluid could easily flow between the test electrodes.
- any reference to methods, products, or systems is understood as a reference to each of those methods, products or systems disjunctively (e.g., “Illustrative embodiment 1-4 is understood as illustrative embodiment 1, 2, 3, or 4.”).
- Illustrative embodiment 1 is a fluid comprising a drilling fluid and a clay stabilizer comprising a potassium salt comprising a plurality of cations, the fluid being injectable into a wellbore.
- Illustrative embodiment 2 is the fluid of any preceding or subsequent illustrative embodiment, wherein the potassium salt is a double salt.
- Illustrative embodiment 3 is the fluid of any preceding or subsequent illustrative embodiment, wherein the clay stabilizer comprises potash alum, camillite, langbeinite, polyhalite, potassium metabisulfite, potassium selenite, potassium tungstate, sodium potassium tartrate, kainite, potassium schoenite, bittern, or hydrates thereof.
- the clay stabilizer comprises potash alum, camillite, langbeinite, polyhalite, potassium metabisulfite, potassium selenite, potassium tungstate, sodium potassium tartrate, kainite, potassium schoenite, bittern, or hydrates thereof.
- Illustrative embodiment 4 is the fluid of any preceding or subsequent illustrative embodiment, wherein the potassium salt comprises more than one potassium cation.
- Illustrative embodiment 5 is the fluid of any preceding or subsequent illustrative embodiment, wherein the potassium salt comprises an aluminum cation.
- Illustrative embodiment 6 is the fluid of any preceding or subsequent illustrative embodiment, wherein the potassium salt comprises a magnesium cation.
- Illustrative embodiment 7 is the fluid of any preceding or subsequent illustrative embodiment, wherein the drilling fluid comprises water, brine, or a hydrocarbon fluid.
- Illustrative embodiment 8 is the fluid of any preceding or subsequent illustrative embodiment, wherein the fluid has a capillary suction time (CST) lower than a CST of a fluid comprising a comparison clay stabilizer, wherein a concentration of the clay stabilizers in each fluid is substantially the same.
- CST capillary suction time
- Illustrative embodiment 9 is the fluid of any preceding or subsequent illustrative embodiment, wherein the CST is at least 20% lower than the CST of the fluid comprising the comparison clay stabilizer.
- Illustrative embodiment 10 is the fluid of any preceding or subsequent illustrative embodiment, wherein the CST is over 50% lower than the CST of the fluid comprising the comparison clay stabilizer.
- Illustrative embodiment 11 is the fluid of any preceding or subsequent illustrative embodiment, wherein the fluid is positionable in the wellbore to reduce swelling of clay particles in reaction to a water-based fluid in the wellbore.
- Illustrative embodiment 12 is the fluid of any preceding or subsequent illustrative embodiment, wherein the potassium salt is present in an amount within a range of about 0.1 wt. % to about 5.0 wt. %.
- Illustrative embodiment 13 is the fluid of any preceding or subsequent illustrative embodiment, wherein the fluid has a plastic viscosity (PV) lower than a PV of a fluid comprising the comparison clay stabilizer, wherein a concentration of the clay stabilizers in each fluid is substantially the same.
- PV plastic viscosity
- Illustrative embodiment 14 is the fluid of any preceding or subsequent illustrative embodiment, wherein the PV is over 60% lower than the PV of the fluid comprising the comparison clay stabilizer.
- Illustrative embodiment 15 is the fluid of any preceding or subsequent illustrative embodiment, wherein the fluid has a yield point (YP) lower than a YP of a of the fluid comprising the comparison clay stabilizer, wherein a concentration of the clay stabilizers in each fluid is substantially the same.
- YP yield point
- Illustrative embodiment 16 is the fluid of any preceding or subsequent illustrative embodiment, wherein the VP is over 60% lower than the YP of the fluid comprising the comparison clay stabilizer.
- Illustrative embodiment 17 is a method comprising contacting a drilling fluid with a potassium salt comprising a plurality of cations to form a treatment fluid; and contacting a wellbore in a clay or shale formation with the treatment fluid.
- Illustrative embodiment 18 is the method of any preceding or subsequent illustrative embodiment, wherein the potassium salt is a double salt.
- Illustrative embodiment 19 is the method of any preceding or subsequent illustrative embodiment, wherein the potassium salt comprises potash alum, camillite, langbeinite, polyhalite, potassium metabisulfite, potassium selenite, potassium tungstate, sodium potassium tartrate, kainite, potassium schoenite, bittern, or hydrates thereof.
- the potassium salt comprises potash alum, camillite, langbeinite, polyhalite, potassium metabisulfite, potassium selenite, potassium tungstate, sodium potassium tartrate, kainite, potassium schoenite, bittern, or hydrates thereof.
- Illustrative embodiment 20 is the method of any preceding or subsequent illustrative embodiment, wherein the drilling fluid comprises water, brine, or a hydrocarbon fluid.
- Illustrative embodiment 21 is the method of any preceding or subsequent illustrative embodiment, further comprising introducing the treatment fluid into a wellbore.
- Illustrative embodiment 22 is the method of any preceding or subsequent illustrative embodiment, further comprising circulating the treatment fluid in the wellbore.
- Illustrative embodiment 23 is the method of any preceding or subsequent illustrative embodiment, further comprising determining a capillary-suction-time (CST) of the treatment fluid once the treatment fluid has contacted the wellbore.
- CST capillary-suction-time
- Illustrative embodiment 24 is the method of any preceding or subsequent illustrative embodiment, wherein the potassium salt is present in the treatment fluid in an amount within a range of about 0.1 wt. % to about 5.0 wt. %.
- Illustrative embodiment 25 is the method of any preceding or subsequent illustrative embodiment, further comprising determining at least one of a capillary-suction-time (CST), plastic viscosity, or yield point of a the fluid once the fluid has contacted the wellbore.
- CST capillary-suction-time
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
Description
Yield Point (VP)=Viscometer Reading at 300 rpm−Plastic Viscosity [Eq. 1]
where the unit of YP is lb/100 ft2 and Plastic Viscosity (PV) is determined from the slope of the shear stress/shear rate line above the yield point or using a direct measure viscometer according to Eq. 2:
Plastic Viscosity (PV)=Reading at 600 rpm−Reading at 300 rpm [Eq. 2]
Claims (20)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/US2018/046209 WO2020032971A1 (en) | 2018-08-10 | 2018-08-10 | Potassium salt treatment fluids for clay stabilization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| US20210355365A1 US20210355365A1 (en) | 2021-11-18 |
| US11479704B2 true US11479704B2 (en) | 2022-10-25 |
Family
ID=69415287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US16/476,982 Active 2039-11-16 US11479704B2 (en) | 2018-08-10 | 2018-08-10 | Potassium salt treatment fluids for clay stabilization |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US11479704B2 (en) |
| WO (1) | WO2020032971A1 (en) |
Citations (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2771421A (en) * | 1954-11-12 | 1956-11-20 | Marathon Corp | Oil well drilling fluids |
| US3734188A (en) | 1970-06-02 | 1973-05-22 | Dow Chemical Co | Well cementing and stimulation method |
| US3737037A (en) | 1971-05-03 | 1973-06-05 | Atlantic Richfield Co | Drilling fluid treatment |
| US3766229A (en) | 1971-08-19 | 1973-10-16 | Dresser Ind | Drilling fluids |
| US4076628A (en) * | 1973-06-22 | 1978-02-28 | Phillips Petroleum Company | Drilling fluid compositions and methods of preparing same |
| US4447341A (en) | 1982-08-27 | 1984-05-08 | W. R. Grace & Co. | Clay stabilizer composition for aqueous drilling fluids |
| US4547297A (en) | 1984-02-07 | 1985-10-15 | W. R. Grace & Co. | High temperature drilling mud stabilizer |
| US4875809A (en) * | 1985-08-24 | 1989-10-24 | Geza Csajtai | Method for stabilizing clay minerals during oil exploitation by steam injection |
| US4988450A (en) | 1988-03-15 | 1991-01-29 | E. I. Du Pont De Nemours And Company | Shale-stabilizing drilling fluid additives |
| US5198415A (en) * | 1991-01-15 | 1993-03-30 | Exxon Production Research Company | Nontoxic, nonchloride, water-base, inhibitive fluid to stabilize water sensitive shale |
| US5342530A (en) * | 1991-02-25 | 1994-08-30 | Nalco Chemical Company | Clay stabilizer |
| US5389146A (en) * | 1993-04-12 | 1995-02-14 | Baroid Technology, Inc. | Grouting composition and method |
| US20090221453A1 (en) * | 2008-02-29 | 2009-09-03 | Sumitra Mukhopadhyay | Treatment Fluid With Oxidizer Breaker System and Method |
| US20110000672A1 (en) | 2007-10-31 | 2011-01-06 | Baker Hughes Incorporated | Clay Stabilization with Nanoparticles |
| US20110071058A1 (en) * | 2009-09-24 | 2011-03-24 | Howard Paul R | Environmentally friendly composition for slickwater application |
| US20120227516A1 (en) | 2009-09-15 | 2012-09-13 | Durst Phototechnik Digital Technology Gmbh | Support Assembly For An Ink-Jet Printing Device |
| US20130015141A1 (en) | 2011-07-11 | 2013-01-17 | Landis Charles R | Novel injection flocculation and compression dewatering unit for solids control and management of drilling fluids and methods relating thereto |
| CN103131397A (en) | 2013-02-16 | 2013-06-05 | 中国石油化工股份有限公司 | Clay stabilizer for drilling fluid and preparation method thereof |
| WO2016156559A1 (en) | 2015-04-01 | 2016-10-06 | Taminco Bvba | Clay stabilizing compositions and use of said compositions for stabilizing water sensitive formations |
| US20170233643A1 (en) * | 2015-08-14 | 2017-08-17 | Halliburton Energy Services, Inc. | Biopolymer Based Cationic Surfactant for Clay Stabilization and Prevention of Sludging |
-
2018
- 2018-08-10 US US16/476,982 patent/US11479704B2/en active Active
- 2018-08-10 WO PCT/US2018/046209 patent/WO2020032971A1/en not_active Ceased
Patent Citations (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2771421A (en) * | 1954-11-12 | 1956-11-20 | Marathon Corp | Oil well drilling fluids |
| US3734188A (en) | 1970-06-02 | 1973-05-22 | Dow Chemical Co | Well cementing and stimulation method |
| US3737037A (en) | 1971-05-03 | 1973-06-05 | Atlantic Richfield Co | Drilling fluid treatment |
| US3766229A (en) | 1971-08-19 | 1973-10-16 | Dresser Ind | Drilling fluids |
| US4076628A (en) * | 1973-06-22 | 1978-02-28 | Phillips Petroleum Company | Drilling fluid compositions and methods of preparing same |
| US4447341A (en) | 1982-08-27 | 1984-05-08 | W. R. Grace & Co. | Clay stabilizer composition for aqueous drilling fluids |
| US4547297A (en) | 1984-02-07 | 1985-10-15 | W. R. Grace & Co. | High temperature drilling mud stabilizer |
| US4875809A (en) * | 1985-08-24 | 1989-10-24 | Geza Csajtai | Method for stabilizing clay minerals during oil exploitation by steam injection |
| US4988450A (en) | 1988-03-15 | 1991-01-29 | E. I. Du Pont De Nemours And Company | Shale-stabilizing drilling fluid additives |
| US5198415A (en) * | 1991-01-15 | 1993-03-30 | Exxon Production Research Company | Nontoxic, nonchloride, water-base, inhibitive fluid to stabilize water sensitive shale |
| US5342530A (en) * | 1991-02-25 | 1994-08-30 | Nalco Chemical Company | Clay stabilizer |
| US5389146A (en) * | 1993-04-12 | 1995-02-14 | Baroid Technology, Inc. | Grouting composition and method |
| US20110000672A1 (en) | 2007-10-31 | 2011-01-06 | Baker Hughes Incorporated | Clay Stabilization with Nanoparticles |
| US20090221453A1 (en) * | 2008-02-29 | 2009-09-03 | Sumitra Mukhopadhyay | Treatment Fluid With Oxidizer Breaker System and Method |
| US20120227516A1 (en) | 2009-09-15 | 2012-09-13 | Durst Phototechnik Digital Technology Gmbh | Support Assembly For An Ink-Jet Printing Device |
| US20110071058A1 (en) * | 2009-09-24 | 2011-03-24 | Howard Paul R | Environmentally friendly composition for slickwater application |
| US20130015141A1 (en) | 2011-07-11 | 2013-01-17 | Landis Charles R | Novel injection flocculation and compression dewatering unit for solids control and management of drilling fluids and methods relating thereto |
| CN103131397A (en) | 2013-02-16 | 2013-06-05 | 中国石油化工股份有限公司 | Clay stabilizer for drilling fluid and preparation method thereof |
| WO2016156559A1 (en) | 2015-04-01 | 2016-10-06 | Taminco Bvba | Clay stabilizing compositions and use of said compositions for stabilizing water sensitive formations |
| US20170233643A1 (en) * | 2015-08-14 | 2017-08-17 | Halliburton Energy Services, Inc. | Biopolymer Based Cationic Surfactant for Clay Stabilization and Prevention of Sludging |
Non-Patent Citations (1)
| Title |
|---|
| International Patent Application No. PCT/US2018/046209, International Search Report and Written Opinion dated May 3, 2019, 13 pages. |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2020032971A1 (en) | 2020-02-13 |
| US20210355365A1 (en) | 2021-11-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2017206066B2 (en) | Methods of logging | |
| US8524638B2 (en) | Method to characterize fracture plugging efficiency for drilling fluids | |
| Bennion et al. | Injection water quality-a key factor to successful waterflooding | |
| US7665523B2 (en) | Compositions and methods for treatment of well bore tar | |
| AU5946590A (en) | Lost circulation fluid for oil field drilling operations | |
| CA2574015C (en) | Clay inhibitors for the drilling industry | |
| US20210071059A1 (en) | Cationic and anionic shale inhibitors and clay stabilizers | |
| US10072198B2 (en) | Self sealing fluids | |
| CA2859236C (en) | Wellbore servicing compositions and methods of making and using same | |
| EP2791272B1 (en) | Compositions and methods for treatment of well bore tar | |
| US11479704B2 (en) | Potassium salt treatment fluids for clay stabilization | |
| CN111433432B (en) | Method for eliminating fluid loss during well construction of oil and gas wells | |
| US11624019B2 (en) | Oil-based fluid loss compositions | |
| NO348645B1 (en) | Detecting amine-based inhibitors in drilling fluids | |
| US10030192B2 (en) | Freeze/thaw stable latex emulsion for treatment of well bore tar | |
| MX2013000415A (en) | Drilling fluid and method for drilling a wellbore. | |
| CA2458504C (en) | Hydrocarbon recovery | |
| US20100222241A1 (en) | Clay Inhibitors for the Drilling Industry | |
| WO2017074306A1 (en) | Salt-free invert emulsions for use in subterranean formation operations | |
| EP2714834B1 (en) | Methods to characterize fracture plugging efficiency for drilling fluids | |
| Sulaiman et al. | The performance of Iraqi palygorskite in salt drilling fluid | |
| US9550932B1 (en) | Additive for drilling fluid used as a shale stabilizing agent in subterranean wellbores | |
| Winarta et al. | Salinity Balance with Non Polar Brine | |
| Basri | Experimental Study Of Potassium In Water-Based Mud (Wbm) For Shale Stability |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: HALLIBURTON ENERGY SERVICES, INC., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CHAVAN, SANDEEP VASANT;KADAM, SUNITA SAMEER;GOSWAMI, SHREYASI;REEL/FRAME:049713/0456 Effective date: 20180828 |
|
| FEPP | Fee payment procedure |
Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT RECEIVED |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: AWAITING TC RESP, ISSUE FEE PAYMENT VERIFIED |
|
| STPP | Information on status: patent application and granting procedure in general |
Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED |
|
| STCF | Information on status: patent grant |
Free format text: PATENTED CASE |